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/*-

 * Copyright (c) 1991 The Regents of the University of California.

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 * 3. [rescinded 22 July 1999]

 * 4. Neither the name of the University nor the names of its contributors

 *    may be used to endorse or promote products derived from this software

 *    without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND

 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE

 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS

 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY

 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

 * SUCH DAMAGE.

 */

/* Mangled into a form that works on Solaris 2/SPARC by Mark Eichin

 * for Cygnus Support, July 1992.

 *

 * Modified to support Solaris 2/x86 by J.W.Hawtin <oolon@ankh.org>, 14/8/96.

 *

 * It must be used in conjunction with sol2-gc1.S, which is used to start

 * and stop process monitoring.

 */

#include "tconfig.h"

#include "tsystem.h"

#include <fcntl.h>              /* For creat.  */

extern void monstartup (char *, char *);

extern void _mcleanup (void);

#ifdef __i386__

static void internal_mcount (void) __attribute__ ((used));

#else

static void internal_mcount (char *, unsigned short *) __attribute__ ((used));

#endif

static void moncontrol (int);

struct phdr {

  char *lpc;

  char *hpc;

  int ncnt;

};

#define HISTFRACTION    2

#define HISTCOUNTER     unsigned short

#define HASHFRACTION    1

#define ARCDENSITY      2

#define MINARCS         50

struct tostruct {

  char *selfpc;

  long count;

  unsigned short link;

};

struct rawarc {

  unsigned long raw_frompc;

  unsigned long raw_selfpc;

  long raw_count;

};

#define ROUNDDOWN(x, y) (((x) / (y)) * (y))

#define ROUNDUP(x, y)   ((((x) + (y) - 1) / (y)) * (y))

/* froms is actually a bunch of unsigned shorts indexing tos.  */

static int profiling = 3;

static unsigned short *froms;

static struct tostruct *tos = NULL;

static long tolimit = 0;

static char *s_lowpc = NULL;

static char *s_highpc = NULL;

static size_t s_textsize = 0;

static int ssiz;

static char *sbuf;

static int s_scale;

/* See profil(2) where this is describe (incorrectly).  */

#define SCALE_1_TO_1    0x10000L

#define MSG "No space for profiling buffer(s)\n"

void

monstartup (char *lowpc, char *highpc)

{

  size_t monsize;

  char *buffer;

  size_t o;

  /* Round lowpc and highpc to multiples of the density we're using

     so the rest of the scaling (here and in gprof) stays in ints.  */

  lowpc = (char *) ROUNDDOWN ((size_t) lowpc,

                              HISTFRACTION * sizeof (HISTCOUNTER));

  s_lowpc = lowpc;

  highpc = (char *) ROUNDUP ((size_t) highpc,

                             HISTFRACTION * sizeof (HISTCOUNTER));

  s_highpc = highpc;

  s_textsize = highpc - lowpc;

  monsize = (s_textsize / HISTFRACTION) + sizeof (struct phdr);

  buffer = sbrk (monsize);

  if (buffer == (void *) -1) {

    write (STDERR_FILENO, MSG, sizeof (MSG));

    return;

  }

  froms = sbrk (s_textsize / HASHFRACTION);

  if (froms == (void *) -1) {

    write (STDERR_FILENO, MSG, sizeof (MSG));

    froms = NULL;

    return;

  }

  tolimit = s_textsize * ARCDENSITY / 100;

  if (tolimit < MINARCS) {

    tolimit = MINARCS;

  } else if (tolimit > 65534) {

    tolimit = 65534;

  }

  tos = sbrk (tolimit * sizeof (struct tostruct));

  if (tos == (void *) -1) {

    write (STDERR_FILENO, MSG, sizeof (MSG));

    froms = NULL;

    tos = NULL;

    return;

  }

  tos[0].link = 0;

  sbuf = buffer;

  ssiz = monsize;

  ((struct phdr *) buffer)->lpc = lowpc;

  ((struct phdr *) buffer)->hpc = highpc;

  ((struct phdr *) buffer)->ncnt = ssiz;

  monsize -= sizeof (struct phdr);

  if (monsize <= 0)

    return;

  o = highpc - lowpc;

  if(monsize < o)

    s_scale = ((float) monsize / o) * SCALE_1_TO_1;

  else

    s_scale = SCALE_1_TO_1;

  moncontrol (1);

}

void

_mcleanup (void)

{

  int fd;

  int fromindex;

  int endfrom;

  char *frompc;

  int toindex;

  struct rawarc rawarc;

  char *profdir;

  const char *proffile;

  char *progname;

  char buf[PATH_MAX];

  extern char **___Argv;

  moncontrol (0);

  if ((profdir = getenv ("PROFDIR")) != NULL) {

    /* If PROFDIR contains a null value, no profiling output is produced.  */

    if (*profdir == '\0') {

      return;

    }

    progname = strrchr (___Argv[0], '/');

    if (progname == NULL)

      progname = ___Argv[0];

    else

      progname++;

    sprintf (buf, "%s/%ld.%s", profdir, (long) getpid (), progname);

    proffile = buf;

  } else {

    proffile = "gmon.out";

  }

  fd = creat (proffile, 0666);

  if (fd < 0) {

    perror (proffile);

    return;

  }

#ifdef DEBUG

  fprintf (stderr, "[mcleanup] sbuf %#x ssiz %d\n", sbuf, ssiz);

#endif /* DEBUG */

  write (fd, sbuf, ssiz);

  endfrom = s_textsize / (HASHFRACTION * sizeof (*froms));

  for (fromindex = 0; fromindex < endfrom; fromindex++) {

    if (froms[fromindex] == 0) {

      continue;

    }

    frompc = s_lowpc + (fromindex * HASHFRACTION * sizeof (*froms));

    for (toindex = froms[fromindex];

         toindex != 0;

         toindex = tos[toindex].link) {

#ifdef DEBUG

      fprintf (stderr, "[mcleanup] frompc %#x selfpc %#x count %d\n",

               frompc, tos[toindex].selfpc, tos[toindex].count);

#endif /* DEBUG */

      rawarc.raw_frompc = (unsigned long) frompc;

      rawarc.raw_selfpc = (unsigned long) tos[toindex].selfpc;

      rawarc.raw_count = tos[toindex].count;

      write (fd, &rawarc, sizeof (rawarc));

    }

  }

  close (fd);

}

/* Solaris 2 libraries use _mcount.  */

#if defined __i386__

asm(".globl _mcount\n"

    "_mcount:\n"

    "   jmp     internal_mcount\n");

#elif defined __x86_64__

/* See GLIBC for additional information about this technique.  */

asm(".globl _mcount\n"

    "   .type   _mcount, @function\n"

    "_mcount:\n"

    /* The compiler calls _mcount after the prologue, and does not

       save any of the registers.  Therefore we must preserve all

       seven registers which may contain function arguments.  */

    "   subq    $0x38, %rsp\n"

    "   movq    %rax, (%rsp)\n"

    "   movq    %rcx, 0x08(%rsp)\n"

    "   movq    %rdx, 0x10(%rsp)\n"

    "   movq    %rsi, 0x18(%rsp)\n"

    "   movq    %rdi, 0x20(%rsp)\n"

    "   movq    %r8, 0x28(%rsp)\n"

    "   movq    %r9, 0x30(%rsp)\n"

    /* Get SELFPC (pushed by the call to this function) and

       FROMPCINDEX (via the frame pointer).  */

    "   movq    0x38(%rsp), %rdi\n"

    "   movq    0x8(%rbp), %rsi\n"

    "   call    internal_mcount\n"

    /* Restore the saved registers.  */

    "   movq    0x30(%rsp), %r9\n"

    "   movq    0x28(%rsp), %r8\n"

    "   movq    0x20(%rsp), %rdi\n"

    "   movq    0x18(%rsp), %rsi\n"

    "   movq    0x10(%rsp), %rdx\n"

    "   movq    0x08(%rsp), %rcx\n"

    "   movq    (%rsp), %rax\n"

    "   addq    $0x38, %rsp\n"

    "   retq\n");

#elif defined __sparc__

/* The SPARC stack frame is only held together by the frame pointers

   in the register windows. According to the SVR4 SPARC ABI

   Supplement, Low Level System Information/Operating System

   Interface/Software Trap Types, a type 3 trap will flush all of the

   register windows to the stack, which will make it possible to walk

   the frames and find the return addresses.

        However, it seems awfully expensive to incur a trap (system

   call) for every function call. It turns out that "call" simply puts

   the return address in %o7 expecting the "save" in the procedure to

   shift it into %i7; this means that before the "save" occurs, %o7

   contains the address of the call to mcount, and %i7 still contains

   the caller above that. The asm mcount here simply saves those

   registers in argument registers and branches to internal_mcount,

   simulating a call with arguments.

        Kludges:

        1) the branch to internal_mcount is hard coded; it should be

   possible to tell asm to use the assembler-name of a symbol.

        2) in theory, the function calling mcount could have saved %i7

   somewhere and reused the register; in practice, I *think* this will

   break longjmp (and maybe the debugger) but I'm not certain. (I take

   some comfort in the knowledge that it will break the native mcount

   as well.)

        3) if builtin_return_address worked, this could be portable.

   However, it would really have to be optimized for arguments of 0

   and 1 and do something like what we have here in order to avoid the

   trap per function call performance hit.

        4) the atexit and monsetup calls prevent this from simply

   being a leaf routine that doesn't do a "save" (and would thus have

   access to %o7 and %i7 directly) but the call to write() at the end

   would have also prevented this.

   -- [eichin:19920702.1107EST]  */

asm(".global _mcount\n"

    "_mcount:\n"

    /* i7 == last ret, -> frompcindex.  */

    "   mov     %i7, %o1\n"

    /* o7 == current ret, -> selfpc.  */

    "   mov     %o7, %o0\n"

    "   b,a     internal_mcount\n");

#endif

static void

#ifdef __i386__

internal_mcount (void)

#else

internal_mcount (char *selfpc, unsigned short *frompcindex)

#endif

{

  struct tostruct *top;

  struct tostruct *prevtop;

  long toindex;

  static char already_setup;

#ifdef __i386__

  char *selfpc;

  unsigned short *frompcindex;

  /* Find the return address for mcount and the return address for mcount's

     caller.  */

  /* selfpc = pc pushed by mcount call.

     This identifies the function that was just entered.  */

  selfpc = (void *) __builtin_return_address (0);

  /* frompcindex = pc in preceding frame.

     This identifies the caller of the function just entered.  */

  frompcindex = (void *) __builtin_return_address (1);

#endif

  if(!already_setup) {

    extern char etext[];

    already_setup = 1;

#if defined __i386__

    /* <sys/vmparam.h> USERSTACK.  */

    monstartup ((char *) 0x8048000, etext);

#elif defined __x86_64__

    monstartup (NULL, etext);

#elif defined __sparc__

    {

      extern char _start[];

      extern char _init[];

      monstartup (_start < _init ? _start : _init, etext);

    }

#endif

    atexit (_mcleanup);

  }

  /* Check that we are profiling and that we aren't recursively invoked.  */

  if (profiling) {

    goto out;

  }

  profiling++;

  /* Check that frompcindex is a reasonable pc value.  For example: signal

     catchers get called from the stack, not from text space.  too bad.  */

  frompcindex = (unsigned short *) ((long) frompcindex - (long) s_lowpc);

  if ((unsigned long) frompcindex > s_textsize) {

    goto done;

  }

  frompcindex = &froms[((long) frompcindex) / (HASHFRACTION * sizeof (*froms))];

  toindex = *frompcindex;

  if (toindex == 0) {

    /* First time traversing this arc.  */

    toindex = ++tos[0].link;

    if (toindex >= tolimit) {

      goto overflow;

    }

    *frompcindex = toindex;

    top = &tos[toindex];

    top->selfpc = selfpc;

    top->count = 1;

    top->link = 0;

    goto done;

  }

  top = &tos[toindex];

  if (top->selfpc == selfpc) {

    /* arc at front of chain; usual case.  */

    top->count++;

    goto done;

  }

  /* Have to go looking down chain for it.  Top points to what we are

     looking at, prevtop points to previous top.  We know it is not at the

     head of the chain.  */

  for (; /* goto done */; ) {

    if (top->link == 0) {

      /* top is end of the chain and none of the chain had top->selfpc ==

         selfpc, so we allocate a new tostruct and link it to the head of

         the chain.  */

      toindex = ++tos[0].link;

      if (toindex >= tolimit) {

        goto overflow;

      }

      top = &tos[toindex];

      top->selfpc = selfpc;

      top->count = 1;

      top->link = *frompcindex;

      *frompcindex = toindex;

      goto done;

    }

    /* Otherwise, check the next arc on the chain.  */

    prevtop = top;

    top = &tos[top->link];

    if (top->selfpc == selfpc) {

      /* There it is.  Increment its count move it to the head of the

         chain.  */

      top->count++;

      toindex = prevtop->link;

      prevtop->link = top->link;

      top->link = *frompcindex;

      *frompcindex = toindex;

      goto done;

    }

  }

 done:

  profiling--;

  /* ... and fall through. */

 out:

  /* Normal return restores saved registers.  */

  return;

 overflow:

  /* Halt further profiling.  */

  profiling++;

#define TOLIMIT "mcount: tos overflow\n"

  write (STDERR_FILENO, TOLIMIT, sizeof (TOLIMIT));

  goto out;

}

/* Control profiling.  Profiling is what mcount checks to see if all the

   data structures are ready.  */

static void

moncontrol (int mode)

{

  if (mode) {

    /* Start.  */

    profil ((unsigned short *) (sbuf + sizeof (struct phdr)),

            ssiz - sizeof (struct phdr), (size_t) s_lowpc, s_scale);

    profiling = 0;

  } else {

    /* Stop.  */

    profil ((unsigned short *) 0, 0, 0, 0);

    profiling = 3;

  }

}